For example, when performing an allocating work for a wire (liner body), a wire-tensioning apparatus equipped with wire grippers coupled at both ends of an extensible rod-shaped body is used to create looseness in a portion where an allocating work is performed by pulling the wire. The wire-tensioning apparatus grips the wire with the wire grippers on both sides, then shortens the interval between the wire grippers coupled to both ends of the rod-shaped body by decreasing the length of the rod-shaped body to thereby create looseness in the electric wire between both ends gripped by the wire grippers. The wire-allocating work can be easily performed by cutting desired portions in the loosened electric wire. A wire gripper disclosed in a patent document 1 is opened to the public as prior art of gripping such an electric wire.
In the wire gripper shown in the patent documents 1, a ring portion provided at the backward side of a coupling member is twisted at 15° to 45° relative to the flat surface of the coupling member and an electric wire by twisting. The ring portion of the coupling member having such a structure can make a reliable approach to a linear body without interfering with the linear body. As such, in the wire gripper shown in the patent documents 1, the center position of the ring portion and the center of the linear body are not significantly spaced apart from each other, and the linear body is hardly bent when the linear body is pulled. Thereby, it is possible to minimize damages and so forth created on the surface of the linear body due to the bending of the linear body.